The BladeCenter S Gets a New SAS RAID Disk Module
September 15, 2008 Timothy Prickett Morgan
IBM wants small and medium businesses to adopt the blade server form factor, but the storage options available for blades are not really appropriate for SMB shops. On-blade disk capacity is limited to one or two drives, which means the blade cannot support lots of file capacity and certainly is inappropriate for supporting anything but the most ridiculously modest level of online transaction processing; and storage area networking is well beyond the budget of SMB shops, and a bit like killing a gnat with a cast iron frying pan.
This is one reason why IBM has announced a SAS module storage cage along with the BladeCenter S chassis, which holds up to six drives in a bent piece of metal that slides right in alongside the blade servers. Last week, IBM took storage in the BladeCenter S a bit further when it announced a new SAS RAID controller module as well as support for 750 GB SAS disk drives for those customers who need some serious capacity in their blade chasses.
The controller module marries a SAS disk switch and a RAID disk controller and puts it in the same form factor that legacy switches in the BladeCenter chassis used to take up. The module also has something SMB shops also want–redundancy. So it can have two RAID controllers, two SAS switches, and two battery backups; the unit also connects to two of IBM’s existing six-disk blade storage enclosures. The integrated SAS switch inside the module has two 4X (3 Gb/sec) SAS switches for linking to the disk enclosures and six 1X (also 3 Gb/sec) SAS links back to the blade server hosts inside the BladeCenter S chassis. Each blade server can be configured with redundant links to the disk modules. The new 750 GB SAS drive is a 3.5-inch disk in a slimline, half-height form factor that spins at a creeping 7,200 RPM; these as well as other 3.5-inch disks (in 10K and 15K RPM speeds) can plug into the module. The integrated RAID controller supports mirroring as well as RAID 5 data protection.
The new blade SAS disk module costs $1,069 without any disks inside. It will be available on October 24. Pricing was not announced for the 750 GB disks, which come out on the same day.